Carbon monoxide can directly affect the heart, brain, and vital organs. A little exposure to it can result in fatigue, nausea, headaches, chest pains, and dizziness. In Kathi’s case, she was inhaling the life-threatening gas for years which caused vomiting, muscle weakness, fainting, and confusion. It might also cause the death of a person. The question was how Kathi was never diagnosed for a decade?